Association of acute toxic encephalopathy with litchi consumption in an outbreak in Muzaffarpur, India, 2014: a case-control study.

BACKGROUND: Outbreaks of unexplained illness frequently remain under-investigated. In India, outbreaks of an acute neurological illness with high mortality among children occur annually in Muzaffarpur, the country's largest litchi cultivation region. In 2014, we aimed to investigate the cause and risk factors for this illness. METHODS: In this hospital-based surveillance and nested age-matched case-control study, we did laboratory investigations to assess potential infectious and non-infectious causes of this acute neurological illness. Cases were children aged 15 years or younger who were admitted to two hospitals in Muzaffarpur with new-onset seizures or altered sensorium. Age-matched controls were residents of Muzaffarpur who were admitted to the same two hospitals for a non-neurologic illness within seven days of the date of admission of the case. Clinical specimens (blood, cerebrospinal fluid, and urine) and environmental specimens (litchis) were tested for evidence of infectious pathogens, pesticides, toxic metals, and other non-infectious causes, including presence of hypoglycin A or methylenecyclopropylglycine (MCPG), naturally-occurring fruit-based toxins that cause hypoglycaemia and metabolic derangement. Matched and unmatched (controlling for age) bivariate analyses were done and risk factors for illness were expressed as matched odds ratios and odds ratios (unmatched analyses). FINDINGS: Between May 26, and July 17, 2014, 390 patients meeting the case definition were admitted to the two referral hospitals in Muzaffarpur, of whom 122 (31%) died. On admission, 204 (62%) of 327 had blood glucose concentration of 70 mg/dL or less. 104 cases were compared with 104 age-matched hospital controls. Litchi consumption (matched odds ratio [mOR] 9·6 [95% CI 3·6 - 24]) and absence of an evening meal (2·2 [1·2-4·3]) in the 24 h preceding illness onset were associated with illness. The absence of an evening meal significantly modified the effect of eating litchis on illness (odds ratio [OR] 7·8 [95% CI 3·3-18·8], without evening meal; OR 3·6 [1·1-11·1] with an evening meal). Tests for infectious agents and pesticides were negative. Metabolites of hypoglycin A, MCPG, or both were detected in 48 [66%] of 73 urine specimens from case-patients and none from 15 controls; 72 (90%) of 80 case-patient specimens had abnormal plasma acylcarnitine profiles, consistent with severe disruption of fatty acid metabolism. In 36 litchi arils tested from Muzaffarpur, hypoglycin A concentrations ranged from 12·4 µg/g to 152·0 µg/g and MCPG ranged from 44·9 µg/g to 220·0 µg/g. INTERPRETATION: Our investigation suggests an outbreak of acute encephalopathy in Muzaffarpur associated with both hypoglycin A and MCPG toxicity. To prevent illness and reduce mortality in the region, we recommended minimising litchi consumption, ensuring receipt of an evening meal and implementing rapid glucose correction for suspected illness. A comprehensive investigative approach in Muzaffarpur led to timely public health recommendations, underscoring the importance of using systematic methods in other unexplained illness outbreaks. FUNDING: US Centers for Disease Control and Prevention.

Molecular epidemiology and evolutionary analysis of dengue virus type 2, circulating in Delhi, India.

Dengue virus type 2 (DENV-2) has been associated with severe dengue outbreaks in many countries including India. Its predominance was recorded nearly after a decade in the capital city, Delhi in 2013. The present study characterizes DENV-2 circulated during 2013-2014. Analysis based on envelope (E) gene showed the presence of two clades (I and II) of DENV-2, within the Cosmopolitan genotype. Analysis of time of most recent common ancestor revealed the existence of clade I for more than a decade (95 % HPD 13-16 years) however, clade II showed comparatively recent emergence (95 % HPD 5-13 years). Presence of different clades is of high significance as this may result in increased virus transmission and major outbreaks. Further, the presence of a unique amino acid substitution, Q325H was also observed in an isolate; 14/D2/Del/2013 (KT717981). This substitution falls in immune epitope (epitope id: 150268) and may have important role in host immune response.

Outbreaks of unexplained neurologic illness - Muzaffarpur, India, 2013-2014.

Outbreaks of an unexplained acute neurologic illness affecting young children and associated with high case-fatality rates have been reported in the Muzaffarpur district of Bihar state in India since 1995. The outbreaks generally peak in June and decline weeks later with the onset of monsoon rains. There have been multiple epidemiologic and laboratory investigations of this syndrome, leading to a wide spectrum of proposed causes for the illness, including infectious encephalitis and exposure to pesticides. An association between illness and litchi fruit has been postulated because Muzaffarpur is a litchi fruit-producing region. To better characterize clinical and epidemiologic features of the illness that might suggest its cause and how it can be prevented, the Indian National Centre for Disease Control (NCDC) and CDC investigated outbreaks in 2013 and 2014. Clinical and laboratory findings in 2013 suggested a noninflammatory encephalopathy, possibly caused by a toxin. A common laboratory finding was low blood glucose (<70 mg/dL) on admission, a finding associated with a poorer outcome; 44% of all cases were fatal. An ongoing 2014 investigation has found no evidence of any infectious etiology and supports the possibility that exposure to a toxin might be the cause. The outbreak period coincides with the month-long litchi harvesting season in Muzaffarpur. Although a specific etiology has not yet been determined, the 2014 investigation has identified the illness as a hypoglycemic encephalopathy and confirmed the importance of ongoing laboratory evaluation of environmental toxins to identify a potential causative agent, including markers for methylenecyclopropylglycine (MCPG), a compound found in litchi seeds known to cause hypoglycemia in animal studies. Current public health recommendations are focused on reducing mortality by urging affected families to seek prompt medical care, and ensuring rapid assessment and correction of hypoglycemia in ill children.

Northward movement of East Central South African genotype of Chikungunya virus causing an epidemic between 2006-2010 in India.

INTRODUCTION: Re-emergence of chikungunya virus in South India after a gap of 32 years in 2006 affected over a million people in the Indian subcontinent. We kept a close vigil over the emerging trend of this virus between 2006-2010 with a view to establish the identity of the circulating genotype(s) and to determine the route of virus transmission in different parts of India. METHODOLOGY: Nucleotide sequencing of the E1 gene region from 36 strains of chikungunya virus from three states in northern India was performed for this present study. Forty-four previously reported E1 sequences, retrieved from the global genome data base were used for making a phylogenetic tree. RESULTS: BLAST search revealed 99% homology of the northern Indian strains of the 2006-2010 outbreak with the Reunion Island isolates of 2006. Northern Indian strains of this study clustered with the East Central South African (ECSA) genotype. CONCLUSIONS: Findings indicate that the currently circulating strain of chikungunya virus in northern India had its origin from the 2006 epidemic strain of South India that moved toward northern India via the western central India between 2006-2010 in a phased manner with dominance of the ECSA genotype and not the Asian genotype.

Serological evidence of rickettsial infections in Delhi.

BACKGROUND & OBJECTIVES: Rickettsial infections remain under-diagnosed due to lack of diagnostic facilities in developing world. Here we present our experience at National Centre for Disease Control, Delhi, about a serosurvey done in Delhi for rickettsial disease with easy to perform low cost, low expertise Weil Felix test. METHODS: On the basis of cut-off titre obtained in healthy population, Weil Felix test results were interpreted along with clinical data. Entomological investigation was also carried out in select areas of Delhi. Rodents were trapped from houses and gardens and vector mites were collected. RESULTS: When serum samples were collected during initial 5 yr period from patients with fever of unknown origin, seropositivity was 8.2 per cent whereas when rickettsial infection was kept as one of the differential diagnosis by clinicians seropositivity increased to 33.3 per cent. Rickettsial infections detected were scrub typhus (48.2%) followed by spotted fever group (27.5%) and typhus group (6.8%) during 2005-2009. In preliminary entomological survey vector mite Leptotombidium deliense was found on rodents. INTERPRETATION & CONCLUSIONS: Our findings showed that results of Weil Felix test should not be disregarded, rather clinically compatible cases should be treated to save lives.

Pediatric Scrub typhus in South Sikkim.

We present five cases of paediatric Scrub typhus from Community Health Centre, Namchi, South Sikkim emphasize timely diagnosis of scrub typhus for appropriate management. Response to doxycycline was good, with fever subsiding within 48-72 hrs of starting the treatment. Four out of five cases completely recovered once appropriate medication was given.

Detection of enzootic plague foci in peninsular India.

A continuous serological and bacteriological surveillance in rodents was carried out in peninsular India i.e. Andhra Pradesh, Karnataka and Tamil Nadu to detect the role of different species of rodents in the maintenance of active enzootic plague foci. Live rodents were collected from wild and ruderal/peri-domestic situations by digging and trapping for sera and organ samples. During 1989 to 2007 serological evidence of plague was detected in different species of rodents in peninsular India. Plague antibodies were detected in 243 sera samples in three different rodent species. Sero-positivity (0.042 percent) amongst rodents tested were found in Tatera indica cuvieri (Hardwicke) followed by Rattus rattus and Bandicota bengalensis. Regular plague surveillance work enhanced the possibility of detecting and delimiting plague foci and helped in implementing necessary preventive anti plague measures to prevent the occurrence of human plague.

Toxoplasmosis - An update.

Toxplasmosis is an important zoonotic disease caused by protozoan parasite Toxoplasma gondii. The disease affects one-third of the total world population. Transmission of the disease is mainly by ingestion of food or water contaminated with oocysts. Congenital toxoplasmosis occurs from the transplacental passage of the parasite from mother to fetus. In most adults it does not cause serious illness, but it can cause blindness and mental retardation in congenitally infected children, and it is a devastating disease in immunocompromised individuals. Diagnosis of toxoplasmosis can be established by the direct detection of the parasite or by serological methods. The most commonly used and effective therapeutic regimen is the combination of pyrimethamine with sulfadiazine and folinic acid. This article provides an overview and update on transmission, diagnosis, management, and prevention of toxoplasmosis.

Continued persistence of a single genotype of dengue virus type-3 (DENV-3) in Delhi, India since its re-emergence over the last decade.

BACKGROUND/PURPOSE: The re-emergence of an epidemic strain of dengue virus type-3 (DENV-3) in Delhi in 2003 and its persistence in subsequent years marked a changing trend in dengue virus circulation in this part of India. Its evolving phylogeny over the past decade has not been studied in detail as yet. METHODS: Reverse transcription polymerase chain reaction and sequencing of the CprM gene junction of DENV-3 from different outbreaks since 2003 was carried out. Thirty CprM DENV-3 sequences from this study were compared with 46 other previously reported CprM DENV-3 sequences from India and other countries. Multiple sequence alignment and phylogenetic trees were constructed to determine the extent of genetic heterogeneity and trace the phylogeny of DENV-3. RESULTS: Thirty CprM DENV-3 sequences (Accession numbers AY706096-99, DQ645945-52, EU181201-14, and EU846234-36) were submitted to GenBank. The CprM junction was found to be AT rich (approximately 53%). Nucleotide sequence alignment revealed only nucleotide substitutions. Phylogenetic analysis indicated sustained evolution of a distinct Indian lineage of DENV-3 genotype III in Delhi. CONCLUSION: Active circulation of DENV-3 genotype III over the last decade in Delhi was evident and worrying. This genotype has been implicated in several outbreaks in South-East Asia and other parts of the world.

Serological study of rickettsial diseases in human and rodent population in Chittoor dist. (A.P.).

In India the presence of Rickettsial disease in human is documented in many states however, the data on presence of Rickettsial infection in Andhra Pradesh is very scare. Therefore, a study was undertaken in Chittoor district (A.P.) to see the prevalence of Rickettsial infection in human and rodent population. 3-5 ml of human blood samples were collected from the patients attending the nearest hospitals of Tirumala, Tirupathi, Palmner and Chittoor areas. Live rodents were trapped and blood samples were collected from them during January and February 2008. Sera was separated and tested by Weil Felix test. Two hundred human sera samples were tested. Of these 39 samples were found reactive with Weil Felix antigen. Of the 39 reactive, 31 were male and 8 female. All the human samples were showing reactivity at 1:20 dilution. Out of the 343 rodents samples tested, only 24 samples were showing reactivity. These were reactive at 1:20, 1:40 and 1:80 dilutions with different types of Weil Felix antigens. Eight rodent sera samples were having titer 1:80 with Proteus OXK which is suggestive of presence of Scrub typhus in this region.

Phylogenetic studies reveal existence of multiple lineages of a single genotype of DENV-1 (genotype III) in India during 1956-2007.

BACKGROUND: Dengue virus type 1 (DENV-1) have been mostly circulating silently with dominant serotypes DENV-2 and DENV-3 in India. However recent times have marked an increase in DENV-1 circulation in yearly outbreaks. Many studies have not been carried out on this virus type, leaving a lacunae pertaining to the circulating genotypes, since its earliest report in India. In the present study, we sequenced CprM gene junction of 13 DENV-1 isolated from Delhi and Gwalior (North India) between 2001-2007 and one 1956 Vellore isolate as reference. For comparison, we retrieved 11 other Indian and 70 global reference sequences from NCBI database, making sure that Indian and global isolates from all decades are available for comparative analysis. RESULTS: The region was found to be AT rich with no insertion or deletion. Majority of the nucleotide substitutions were silent, except 3 non-conservative amino acid changes (I --> T, A --> T and L --> S at amino acid positions 59,114 and 155 respectively) in the Indian DENV-1 sequences, sequenced in this study. Except two 1997-98 Delhi isolates, which group in genotype I; all other Indian isolates group in genotype III. All Indian genotype III DENV-1 exhibited diversity among them, giving rise to at least 4 distinct lineages (India 1-4) showing proximity to isolates from diverse geographic locations. CONCLUSION: The extensive phylogenetic analysis revealed consistent existence of multiple lineages of DENV-1 genotype III during the last 5 decades in India.

Emergence of an independent lineage of dengue virus type 1 (DENV-1) and its co-circulation with predominant DENV-3 during the 2006 dengue fever outbreak in Delhi.

OBJECTIVES: The sudden emergence of dengue virus type 1 (DENV-1) and its co-circulation with predominant DENV-3 was the hallmark of the 2006 dengue fever outbreak in Delhi. Viruses that circulated between 1996 and 2005 in the City have been well characterized, but the genomic diversity in 2006 strains is not known. The present study was undertaken to reveal the emerging molecular genotype(s) and evolutionary trend of the viruses responsible for the dengue fever outbreak in Delhi during 2006. STUDY DESIGN: The CprM gene junction of the DENV isolates from the 2006 Delhi dengue fever outbreak were subjected to nucleotide sequencing. Comparative phylogenetic analysis was done using DENV-1 and DENV-3 sequences retrieved from the global database. RESULTS: Multiple sequence alignment revealed only substitutions, with no insertions or deletions. A dendrogram indicated emergence of a distinct lineage of DENV-1 (having similarity with the Comoros/Singapore 1993 and Delhi 1982 strains, but quite different from the Delhi 2005 lineage) and microevolution of the pre-circulating DENV-3. These findings point towards the circulation of two independent lineages of DENV-1 in Delhi during 2005 and 2006. CONCLUSIONS: It is feared that the introduction of an independent lineage of the outbreak-associated strain of DENV-1 and its co-circulation with the deeply-rooted strain of DENV-3 in Delhi may result in yet another, possibly more severe outbreak in the near future.

Prompt laboratory diagnosis in timely containment of a plague outbreak in India.

A focal outbreak of pneumonic plague occurred in a hamlet of village Hatkoti, district Shimla, Himachal Pradesh in the first fortnight of February, 2002. A total of 16 cases with 4 deaths were reported. Diagnosis of plague was confirmed by the laboratory in 10 (63%) cases. Y. pestis was isolated from clinical samples of 3 cases and confirmed by bacteriophage lysis. Molecular tests confirmed the presence of Y. pestis specific pla and F1 genes in 4 cases; DNA fingerprinting had identity with the known sequence of plague bacilli. Paired samples from 5 cases showed more than 4 fold rise and 1 case showed more than 4 fold fall in antibodies against F1 antigen of Y. pestis. The present communication emphasises that timely and systematic laboratory investigations give confirmatory diagnosis in shortest possible time which forms the backbone of the outbreak control in a timely fashion and prevents confusion and controversy.

Knowledge, attitude and practices about animal bites and rabies in general community--a multi-centric study.

Rabies a disease as old as our civilization, continues to be the most feared of all communicable diseases. Despite the availability the state-of-the-art tools which ensure near cent percent protection against rabies, India is the largest contributant to rabies mortality in the world. A multicentric study was carried out from April 2001 to September 2002 with the objective of assessing the knowledge, attitudes, beliefs and practices (KAP) about animal bites and rabies in the general community. The proforma for interviewing the general community was developed and used after field testing. The study was carried out at six selected centres across the country viz. Delhi, Hyderabad, Raipur, Jamnagar, Coonoor and Rajahmundry and was co-ordinated by National Institute of Communicable Diseases (NICD), Delhi, after thorough briefing of designated nodal officers. A total of 1129 (male: female :: 48.5: 51.5) persons in the age group of 18 to 80 years were interviewed in this study. Of these about 751% of the individuals had attended school at some level and rest were illiterates. 68.7% people had heard about rabies. In 60.7% of cases the community associates rabies with dog bite only. Knowledge about appropriate wound toilet was found to be inadequate. Only 360 (31.9%0/) people felt that washing the wound with soap and water was the best option. Application of indigenous products like chillies (11.4%), turmeric (5.6%), lime (6.8%), kerosene oil (2.3%), herbal paste (4.2%) etc was suggested along with visit to occult medicine practitioner (1.5%) as part of the bite wound management. People were not aware of number of injections needed for treatment of animal bites. Multiple reasons viz negligence and ignorance 354 (31.4%), fear of multiple painful injections 365 (32.3%), expensive treatment 169 (15%) and long course requiring daily visits to anti-rabies clinics 73 (6.5%) were cited as reasons for non-compliance of treatment. KAP study suggests that there is need to create awareness amongst the masses regarding epidemiology of the disease and merits of prompt and appropriate post exposure treatment through enhanced IEC activities.